package com.xueyi.auth.handler;

import com.xueyi.common.core.utils.core.ObjectUtil;
import com.xueyi.common.core.utils.core.StrUtil;
import org.springframework.lang.Nullable;
import org.springframework.security.oauth2.core.ClaimAccessor;
import org.springframework.security.oauth2.core.OAuth2AccessToken;
import org.springframework.security.oauth2.core.endpoint.OAuth2ParameterNames;
import org.springframework.security.oauth2.server.authorization.OAuth2TokenType;
import org.springframework.security.oauth2.server.authorization.client.RegisteredClient;
import org.springframework.security.oauth2.server.authorization.settings.OAuth2TokenFormat;
import org.springframework.security.oauth2.server.authorization.token.OAuth2TokenClaimsContext;
import org.springframework.security.oauth2.server.authorization.token.OAuth2TokenClaimsSet;
import org.springframework.security.oauth2.server.authorization.token.OAuth2TokenContext;
import org.springframework.security.oauth2.server.authorization.token.OAuth2TokenCustomizer;
import org.springframework.security.oauth2.server.authorization.token.OAuth2TokenGenerator;
import org.springframework.util.Assert;
import org.springframework.util.CollectionUtils;

import java.time.Instant;
import java.util.Collections;
import java.util.Map;
import java.util.Set;
import java.util.UUID;

/**
 * 自定义令牌
 *
 * @author xueyi
 */
public class CustomTokenGenerator implements OAuth2TokenGenerator<OAuth2AccessToken> {

    private OAuth2TokenCustomizer<OAuth2TokenClaimsContext> accessTokenCustomizer;

    @Nullable
    @Override
    public OAuth2AccessToken generate(OAuth2TokenContext context) {
        if (ObjectUtil.notEqual(OAuth2TokenType.ACCESS_TOKEN, context.getTokenType()) || ObjectUtil.notEqual(OAuth2TokenFormat.REFERENCE, context.getRegisteredClient().getTokenSettings().getAccessTokenFormat()))
            return null;

        String issuer = null;
        if (context.getAuthorizationServerContext() != null) {
            issuer = context.getAuthorizationServerContext().getIssuer();
        }
        RegisteredClient registeredClient = context.getRegisteredClient();

        Instant issuedAt = Instant.now();
        Instant expiresAt = issuedAt.plus(registeredClient.getTokenSettings().getAccessTokenTimeToLive());

        // @formatter:off
        OAuth2TokenClaimsSet.Builder claimsBuilder = OAuth2TokenClaimsSet.builder();
        if (StrUtil.hasText(issuer))
            claimsBuilder.issuer(issuer);
        claimsBuilder.subject(context.getPrincipal().getName()).audience(Collections.singletonList(registeredClient.getClientId())).issuedAt(issuedAt).expiresAt(expiresAt).notBefore(issuedAt).id(UUID.randomUUID().toString());
        if (!CollectionUtils.isEmpty(context.getAuthorizedScopes())) {
            claimsBuilder.claim(OAuth2ParameterNames.SCOPE, context.getAuthorizedScopes());
        }
        // @formatter:on

        if (this.accessTokenCustomizer != null) {
            // @formatter:off
            OAuth2TokenClaimsContext.Builder accessTokenContextBuilder = OAuth2TokenClaimsContext.with(claimsBuilder).registeredClient(context.getRegisteredClient()).principal(context.getPrincipal()).authorizationServerContext(context.getAuthorizationServerContext()).authorizedScopes(context.getAuthorizedScopes()).tokenType(context.getTokenType()).authorizationGrantType(context.getAuthorizationGrantType());
            if (context.getAuthorization() != null) {
                accessTokenContextBuilder.authorization(context.getAuthorization());
            }
            if (context.getAuthorizationGrant() != null) {
                accessTokenContextBuilder.authorizationGrant(context.getAuthorizationGrant());
            }
            // @formatter:on

            OAuth2TokenClaimsContext accessTokenContext = accessTokenContextBuilder.build();
            this.accessTokenCustomizer.customize(accessTokenContext);
        }

        OAuth2TokenClaimsSet accessTokenClaimsSet = claimsBuilder.build();
        return new CustomTokenGenerator.OAuth2AccessTokenClaims(OAuth2AccessToken.TokenType.BEARER, UUID.randomUUID().toString(), accessTokenClaimsSet.getIssuedAt(), accessTokenClaimsSet.getExpiresAt(), context.getAuthorizedScopes(), accessTokenClaimsSet.getClaims());
    }

    /**
     * Sets the {@link org.springframework.security.oauth2.server.authorization.token.OAuth2TokenCustomizer} that customizes the
     * {@link OAuth2TokenClaimsContext#getClaims() claims} for the
     * {@link OAuth2AccessToken}.
     *
     * @param accessTokenCustomizer the {@link org.springframework.security.oauth2.server.authorization.token.OAuth2TokenCustomizer} that customizes the
     *                              claims for the {@code OAuth2AccessToken}
     */
    public void setAccessTokenCustomizer(OAuth2TokenCustomizer<OAuth2TokenClaimsContext> accessTokenCustomizer) {
        Assert.notNull(accessTokenCustomizer, "accessTokenCustomizer cannot be null");
        this.accessTokenCustomizer = accessTokenCustomizer;
    }

    private static final class OAuth2AccessTokenClaims extends OAuth2AccessToken implements ClaimAccessor {

        private final Map<String, Object> claims;

        private OAuth2AccessTokenClaims(TokenType tokenType, String tokenValue, Instant issuedAt, Instant expiresAt, Set<String> scopes, Map<String, Object> claims) {
            super(tokenType, tokenValue, issuedAt, expiresAt, scopes);
            this.claims = claims;
        }

        @Override
        public Map<String, Object> getClaims() {
            return this.claims;
        }

    }

}